ISS Inc. and the Cognitive Neuroimaging Laboratory (CNL) at the University of Illinois propose to develop and construct the prototype of a novel instrument for full-head non-invasive near infrared (NIR) functional imaging of the human brain (which we call "Opticortex"). NIR imaging, because of its combination of spatial and temporal resolution, its ability to image both neuronal and hemodynamic activity, and its relatively low cost, complements and enhances current human brain imaging methods, and is particularly useful for the investigation of whole brain cognitive networks and for studies of neurovascular coupling. Opticortex features include: (a) a large number of channels, providing full-head coverage and greater spatial resolution, using up to 128 laser sources and 60 detectors;and (b) programmable multiplexing to allow for "adaptive" recording montage design. During Phase I, we will explore two further features: (a) multiple simultaneous modulation frequencies to limit channel crosstalk and increase sampling rate;(b) variable modulation frequencies (from 50 to 300 MHz) to optimize S/N, spatial resolution and depth penetration for specific medical applications. The new systems will also include flexible, modular and integrated software for: (a) data acquisition;(b) co-registration of the optical data with anatomical images of the brain;(c) pre-analysis, artifact rejection and/or correction, averaging, image generation, statistical analysis;and (d) interfacing with other brain imaging software. The modular nature of the instrument confers several application and commercialization advantages. For some applications (e.g. infants or region-of-interest recording) a version featuring 32 sources and 15 detectors will be sufficient;yet, such instrument can be upgraded to the full configuration should the need arise, and for research involving full- head studies in adults. PUBLIC HEALTH RELEVANCE: MRI is the technique of choice for imaging functional changes in the brain activity. It is costly (about $3M) and it requires special facilities. Data acquisition time is of the order of 20 minutes and during the registration session the patient is required to stand still inside the measuring body. We propose to build an instrument that is portable (it can be housed in a doctor's office), affordable (less than $500K), insensitive to motion artifacts (suitable for measurements on infants and children). The new frequency-domain instrument, which we call Opticortex, features 128 light sources and 60 detectors;it is intended for the measurement of the fast and slow activities of the entire brain. The Opticortex will launch a novel range of applications in cognitive neurosciences (task related responses in adults, the effect of aging on the sensory cortex, brain development in infants, linguistics) and it will open the door for the investigation of relevant medical applications: as it will selectively probe different depths of the brain, potential applications in the area of stroke recovery and neurosurgery, the study of epilepsy and depression will be within the reach of the medical research community.